Tracking Ca2+ ATPase intermediates in real time by x-ray solution scattering
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Dokumenter
- OA-Tracking Ca2+ ATPase intermediates in real time by x-ray solution scattering
Forlagets udgivne version, 1,79 MB, PDF-dokument
Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) transporters regulate calcium signaling by active calcium ion reuptake to internal stores. Structural transitions associated with transport have been characterized by x-ray crystallography, but critical intermediates involved in the accessibility switch across the membrane are missing. We combined time-resolved x-ray solution scattering (TR-XSS) experiments and molecular dynamics (MD) simulations for real-time tracking of concerted SERCA reaction cycle dynamics in the native membrane. The equilibrium [Ca2] E1 state before laser activation differed in the domain arrangement compared with crystal structures, and following laser-induced release of caged ATP, a 1.5-ms intermediate was formed that showed closure of the cytoplasmic domains typical of E1 states with bound Ca2+ and ATP. A subsequent 13-ms transient state showed a previously unresolved actuator (A) domain arrangement that exposed the ADP-binding site after phosphorylation. Hence, the obtained TR-XSS models determine the relative timing of so-far elusive domain rearrangements in a native environment.
Originalsprog | Engelsk |
---|---|
Artikelnummer | eaaz0981 |
Tidsskrift | Science Advances |
Vol/bind | 6 |
Udgave nummer | 12 |
ISSN | 2375-2548 |
DOI | |
Status | Udgivet - 2020 |
Antal downloads er baseret på statistik fra Google Scholar og www.ku.dk
ID: 239812687